Profiling of workpieces



Se t, 16, 1969 J. MARCOVITCH PROFILING OF WORKPIECES 3 Sheets-Sheet 1Filed Sept. 24, 1965 M r m V m (A4000 MAAJCOV/ 766 Sept. 16, 69 J.MARc'ovncH 3,465,918

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w w wmww kw H mwa r Mm 6 5 United States Patent 3,466,918 PROFILING 0FWORKPIECES Jacob Marcovitch, Johannesburg, Republic of South Africa,assignor to Rotary Profiles Anstalt, Vaduz, Liechtenstein Filed Sept.24, 1965, Ser. No. 489,903 Claims priority, application Republic ofSouth Africa, Sept. 30, 1964, 64/4,662 Int. Cl. B21b 1/16, 19/12; B21d3/02 U.S. Cl. 72366 9 Claims ABSTRACT OF THE DISCLOSURE The disclosurerelates to a method of rolling a workpiece that is a figure ofrevolution to reduce or profile it. The workpiece is nipped in a throatdefined by two relatively moving bodies so that it is drawn through thethroat, rotating about its axis as it does so; the bodies being forcedtowards each other to narrow the throat after the workpiece has beennipped in it, so to increase the reduction imposed on the workpiecewithout increasing the throat length.

This invention relates to the profiling of workpieces that are figuresof revolution by passing them through a convergent throat having movingwalls that nip the workpiece and drawn it into and through the throat.The throat is usually defined by two opposed rollers, at least one ofwhich is rotated. The rollers may be side by side or one may be hollowand contain the other. Another arrangement is one in which the throat isdefined by two opposed rectilinear surfaces that converge and which aremounted for relative oscillation.

Profiling of workpieces in this manner has considerable advantages overconventional machining methods, such as economy of material and speed ofproduction. It has advantages, too, over profiling techniques which usetwo relatively movable rollers rotating at the same peripheral speed,that squeeze the workpiece between them, while rotating it but keepingits axis aligned with the axes of the rollers. These techniques requiresome means whereby the workpiece is maintained in position while it isbeing squeezed, and each workpiece must be individually brought intoposition, profiled and then withdrawn to make room for the next. Wherethe workpieces are nipped and drawn through a throat, a succession ofworkpieces can be made to follow one another through the throat, so thatproduction is continuous. On the other hand, the technique of squeezingthe workpiece between relatively movable rollers is capable of impartinggreater deformation to a workpiece than is the system in which theworkpieces pass through a throat between fixed rollers. This is sobecause the diminution in width in the throat between the point wherethe workpiece is nipped by the ro'lers, and the narrowest point of thethroat, which determines the greatest possible deformation, isnecessarily limited, so that the system is not of utility for other thansmall deformations or for burnishing of workpieces or the formation offine grooves or threads.

The object of this invention is to provide a method which combines theadvantages of both systems.

The invention provides a method of profiling workpieces that ane figuresof revolution, which consists in offering a workpiece to a convergingthroat defined by opposed surfaces of a pair of bodies, nipping theworkpiece in the throat with its axis substantially at right angles tothe direction in which the throat converges, moving the bodiesrelatively to each other to rotate the workpiece about its axis and drawit through the throat with the axis of the workpiece moving continuouslyalong the throat; and,

3,466,918 Patented Sept. 16., 1969 after the workpiece has been nippedin the throat, forcing the surfaces relatively towards each other tonarrow the throat.

If the surfaces be provided by two rollers, one roller may have a fixedaxis and the other be movable towards and away from the fixed roller; orboth axes may be movable.

The utility of the method of the invention is that as great adeformation is available as with the movableroller systems, but thedisadvantages of having to maintain the workpiece centrally by means ofa rest or other means are eliminated.

Apparatus to carry out the method of the invention consists of twojuxtaposed surfaces defining between them a convergent throat having anincluded angle calculated to nip a workpiece and draw it into thethroat, means so to move the surfaces relatively to each other that theresultant movement is in the direction of convergence of the throat, andmeans to force the surfaces together to diminish the width of thethroat.

If the surfaces be provided by rollers, the rollers may be juxtaposed;or one may be hollow with the second within its cavity.

The roller design may be such that the roller surfaces act on aworkpiece directly; or such that the surface of one roller acts on anannular workpiece directly while the other buttresses a core or mandrelloosely contained within the cavity of the workpiece.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a schematic representation of juxtaposed rollers,

FIGURE 2 is a similar view of the same arrangement with the workpiecefurther advanced,

FIGURE 3 is a schematic view of two rollers, one within the cavity ofthe other.

FIGURE 4 is a schematic view showing juxtaposed rollers with an annularworkpiece,

FIGURE 5 is a schematic view of one means of forcing the rollerstogether,

FIGURE 6 is a horizontal section on the line 6-6 of FIGURE 5,

FIGURE 7 is a schematic side view of an arrangement in which thesurfaces are rectilinear,

FIGURE 8 is a schematic view of an arrangement in which a ring is usedto control the outer diameter of the finished product, and

FIGURE 9 is a fragmentary view illustrating the formation of an annularproduct from a blank.

In FIGURES 1 and 2, the surfaces defining the throat 10 are theperipheries 12, 14 of two juxtaposed rollers 16, 18, which are mountedfor rotation about their axes. The directions of peripheral movement atthe throat 10 are opposite to each other but the speed of one roller isgreater than that of the other. The resultant relative movement is inthe direction of the throat 10 from the side at which workpieces such asthat shown at 20 are fed into the throat.

It is not necessary to particularize about the required angle of nip,differential speed and so on, necessary to nip a workpiece and draw itinto the throat 10. The parameters called for are well-known in the art.

In FIGURE 1 the workpiece 20 has been offered to the throat 10 and hasbeen nipped between the rollers. Immediately after the workpiece hasbeen nipped the rollers are forcibly moved inwardly relatively towardseach other. If the axes of the rollers remained fixed, the passage ofthe workpiece 20 through the throat would impose not much deformation,because the throat width does not much decrease between the point of nipand the narrowest width. However, when the rollers are movedprogressively forcibly together relatively to each other, this narrowsthe throat 10. The workpiece continues to advance as the rollers rotateand draw it further into the narrowing throat, and the diminished widthof the throat due to the natural converging of the throat and theimposed inward movement of the rollers means that the workpiece can bevery much more deformed than if the rollers had not been relativelymoved.

Preferably, the imposed inward movement of the rollers is stopped justbefore the axis of the workpiece reaches the line AA joining the axes ofthe rollers 16, 18, to allow time for the workpiece to be finished ofi.

In FIGURE 3, one roller 22 is hollow and the second roller 24 is mountedwithin its cavity. The workpiece 26 is shown advancing into the throat28, and, when it has been nipped, the rollers are moved to bring theiropposed surfaces defining the throat more closely together.

In FIGURE 4, the arrangement is akin to that of FIG- URE 1, but theworkpiece 30 is an annulus, the outer surface of which is in contactwith the surface of the outer roller 32. A cylindrical mandrel 34 islocated within the annulus and projects from it to each side. Beyond theannulus, the mandrel is in contact with the outer surface of the roller36. The roller 36 is circumferentially grooved at 38 to accommodate theannulus.

The annulus and mandrel are together offered to the throat 40 and arenipped. The annulus rotates as it negotiates the throat and is deformedbetween the outer roller and the mandrel. When the mandrel and annulusare nipped, the roller 32 is moved towards the surface of the roller 36,or vice versa, to narrow the throat 40.

In FIGURES and 6, a means is shown to move one roller towards the otherto narrow the throat 42. One roller, 44, has its shaft 46 journalled ina sleeve 48, eccentrically. The sleeve is mounted for rotation about itsaxis by being contained in a bearing 50. An arm 51, integral with thesleeve, projects radially from it and its outer end is pivotallyconnected to one end of a hydraulic jack 52, the other end being fixed.When the time comes to move the rollers relatively together, the jack isactuated to extend its piston and to rotate the sleeve, whereupon theaxle 46 is forcibly displaced towards the other roller to narrow thethroat 42 and to impose increased deformation upon the workpiece 54.Once the workpiece has negotiated the throat, the jack is collapsed toreturn the roller 44 to its initial position, ready for the nextworkpiece.

The jack may be operated automatically upon the workpiece reaching apredetermined point in its orbit, by, for instance, triggering a switchwhich opens a valve 58 to feed fluid into the jack; a second switchbeing automatically operated by the workpiece as it leaves the throat,to open a release valve to exhaust fluid from the jack, when a springreturns the sleeve to its starting point or fluid is admitted to thejack to collapse it.

Alternatively, the jack may be manually controlled.

In FIGURE 7, a roof 62 has a sloping portion 64, extended as a levelpart 66. Below it, is a floor 68 that is parallel with the level part 66of the roof. The floor is fixed longitudinally. The roof is backed by afixed backing 70 and is guided on it, for reciprocating sliding movementunder the compulsion of a power-driven pusher 72. The base is movableupwardly by a series of hydraulic jacks 74.

A workpiece 76 is offered to the convergent throat 78 defined by thesloping part 64 of the roof and the coin cident portion of the floor. Asthe roof moves to the left, the workpiece is nipped and is drawn intothe throat 78. Immediately this happens, the jacks 74 are actuated toforce the floor upwardly to narrow the throat 78. Once through thethroat, the reduced workpiece is received between the parallel lands 66,69, until the advance of the roof 68 causes its trailing edge 80 to passbeyond the workpiece, which is removed.

The apparatus of FIGURE 7 can also be used to deform annuli, byproviding a slot or groove in one or other of the floor or roof, toaccommodate the annulus, and by using a mandrel, and, if desired, acontrol ring outside the annulus to contain the distension of the ringand thus prescribe with precision the diameter or profile of thefinished product.

In FIGURE 8, an arrangement like that in FIGURE 4 is shown, but a ring84 is provided outside the annulus 86, to limit the distension of theworkpiece as it passes through the throat 88 and thus preciselyprescribe the outer diameter or profile of the finished product. Afterthe throat has been traversed, the ring and the workpiece are separated.

It will be appreciated that the hydraulic jacks illustrated to move therollers or the floor is only one of many possible ways in which therequired movement can be achieved.

In order to obtain a finished product of exact required diameter usingthe methods outlined above, it is necessary to start ofi with anaccurately prepared blank workpiece and all blanks of a series have tobe almost identical in weight and dimensions. This preparation usuallyinvolves machining, which defeats the object of the process to someextent.

In an annulus the dimensions that are usually important are the outer orinner diameters. Getting the axial dimension precise is not usuallytroublesome because a final grinding operation to remove overflow iseasily performed.

In the arrangement of FIGURE 9, the outer diameter of the annulus 90 isheld to a requisite dimension by encasing the blank (dotted at 91)within a control ring 92, the inner diameter of which is exactly thatwhich is required for the outer diameter of the workpiece, and which isof very hard material relatively to the material of the workpiece, forexample cemented tungsten carbide, when the the workpieces are of mildsteel.

The control ring 92, with the workpiece 90 within its cavity, isinserted between inner and outer rollers 94, 96, with a mandrel 98between the outer surface of the inner roller 94 and the inner surfaceof the workpiece 90, as in the case of the FIGURE 4 arrangement; or, ifthe rollers be solid and juxtaposed, then as in the case of the FIGURES1 and 2 arrangement.

In this case, as in the case of the FIGURE 8 arrangement, there is, ofcourse, the problem of extracting the finished product from the cavityof the control ring. If the nature of the product permits, the outerdiameter may have a draw taper, and lubricant can be spread between thejuxtaposed surfaces to facilitate extraction. If a draw taper is notpracticable, the control ring material may be so selected that theditferential coefiicients of expansion of control ring and workpiececause the finished workpiece to loosen in the control ring on cooling orheating, sufliciently to permit extraction. The cooling may follow thenatural heating due to the deformation of the workpiece, or theworkpiece may be heated before or during handling.

I claim:

1. A method of profiling workpieces that are figures of revolution whichconsists in offering a workpiece to a converging throat defined byopposed surfaces of a pair of bodies nipping the workpiece in the throatwith its axis substantially at right angles to the direction in whichthe throat converges, moving the bodies relatively to each other torotate the workpiece about its axis and draw it through the throat withthe axis of the workpiece moving continuously along the throat; and,after the workpiece has been nipped in the throat, forcing the bodiesrelatively towards each other to narrow the throat.

2. A continuous method of profiling workpieces that are figures ofrevolution which consists in passing a stream of workpieces individuallyin succession through a throat defined by a pair of opposed rollers thatare rotated about their axes at constant speeds; nipping each workpiecein the throat and drawing it through the throat by the rotary action ofthe rollers with the axis of the workpiece moving continuously along thethroat; and intermittently forcing the rollers relatively together tonarrow the throat and thereafter drawing the rollers relatively apart totheir original positions; such intermittent motion being imposed on therollers each time a workpiece is nipped in the throat.

3. A method of profiling workpieces that are figures of revolution whichconsists in oifering a workpiece to a convergent-divergent throatdefined by a pair of opposed rollers that are rotating about their axesat constant but relatively different peripheral speeds; nipping theworkpiece in the throat, with its axis substantially parallel to theaxes of the rollers, for the workpiece to be drawn through the throat bythe rotary action of the rollers with the axis of the workpiece movingcontinuously along the throat; narrowing the throat, after so nippingthe workpiece, by forcing the roller axes relatively towards each other;and maintaining the throat in this narrowed condition for an intervalwhile the workpiece advances along the throat.

4. The method of claim 3 in which the rollers are juxtaposed and theirperipheries defining the throat are rotated in the same direction.

5. The method of claim 3 in which one roller is hollow and the second iscontained within its cavity, in which the peripheries of the rollersdefining the throat are rotated in opposite directions.

6. The method of claim 3 as applied to the profiling of annuli,including the steps of threading a cylindrical mandrel through thecavity of the annulus, and drawing the workpiece and the mandrel intoand through the throat with the workpiece in contact with one roller andthe mandrel in contact with the other roller.

7. The method of claim 6 including the step of surrounding the workpiecewith a ring; during the passage of the workpiece through the throatexpanding the workpiece into contact with the inner face of the ring;after it has traversed the throat withdrawing the workpiece from themandrel; and separating the workpiece from the ring.

8. The method of claim 7 including the step of limiting the axialmovement of the ring, as it is being deformed, in one axial directiononly, to define one end of the annulus, and after separation of theworkpiece from the ring, removing surplus metal at the other end of theworkpiece.

9. A method of profiling cylindrical or cylindroidal workpieces whichconsists in offering a workpiece to a convergent throat defined bysubstantially rectilinear surfaces of tWo bodies that are movablerelatively to each other, nipping the workpiece in the throat, with itsaxis substantially at right angles to the direction in which the throatextends; moving one body relatively to the other in a directionsubstantially parallel to one of the surfaces defining the throat, so toroll the workpiece between the bodies; and While the bodies arerelatively moving in that direction, forcing them relatively together tonarrow the throat.

References Cited UNITED STATES PATENTS 154,685 9/1874 Lafferty et a1.72-91 2,061,034 11/1936 Lennon 72-9l 3,345,845 10/ 1967 Marcovitch eta1. 7291 MILTON S. MEHR, Primary Examiner US. Cl. X.R.

